Topic 2 Microbial cells: Structure & Function Flashcards
Two Basic Differences Between Prokaryotes and Eukaryotes
- Eukaryotes contain numerous compartments (organelles) and prokaryotes generally lack organelles
- Prokaryotes are generally much smaller in size: equivalent to a mitochondrion
Surface area to volume ratio affects
how quickly cells exchange nutrients and waste with their environment
small cells can generally
- grow (reproduce) more quickly
- Also means less time/energy to replicate cell
The fundamental difference between prokaryotes and eukaryotes is the presence of
membrane-bound compartments
_________ cells contain multiple membrane-bound compartments,___________ cells generally do not
Eukaryotic Prokaryotic
Eukaryotic compartments: Nucleus
Defining characteristic of eukaryotic cells
- Separates genetic material (DNA) from the rest of the cell
- Transcription/translation uncoupled (unlike prokaryotes) – ribosomes outside of the nucleus
- Proteins related to DNA replication, transcription, etcmust be translocated into nucleus
Eukaryotic compartments: Mitochondria
Almost universal amongst eukaryotes (a few protists lack mitochondria)
- Vary in number, shape between different eukaryotes/cell types/tissues
- Energy center of the cell – site of respiration, ATP production
- Contain own genomes, ribosomes
Eukaryotic compartments: Golgi Complex & Endoplasmic Reticulum
Involved in modifying and sorting proteins (and other molecules) to be translocated to other parts of the cell or secreted from the cell.
- glycosylation
- Proteins & other molecules are packaged into vesicles and trafficked around the cell (and secreted from the cell)
In the golgi and ER, One important modification is
glycosylation – many eukaryotic proteins have glycans (sugars) added
Cytoskeleton:
Dynamic protein filament network involved in cell shape, transport within cell, cell movement and more
Vacuoles :
Membrane bound compartment, often for storing nutrients and/or waste.
Lysosomes are
specialized vacuoles found in many animal cells that contain enzymes to break down incoming nutrients
Chloroplasts:
Found in phototrophs (like plants and algea) – contain the machinery for photosynthesis
Vesicles :
Small, membrane bound compartments used extensively to traffic materials around the cell, into/out of cells and between organelles
Cell Wall:
Some eukaryotes have one (plants, fungi), others don’t (animals). Much diversity in structure.